Associations of alcohol with the human gut microbiome and prospective health outcomes in the FINRISK 2002 cohort

Alcohol remains a global risk factor for non-communicable diseases with the gut microbiome emerging as a novel elucidator. A study published in the European journal of Nutrition investigated how the gut microbiome associates with alcohol on a population level, if there is mediation reflected in health outcomes, and how functional potential is related.
The study sample consisted of 4,575 shallow-shotgun sequenced faecal samples from the FINRISK 2002 cohort (25-74yrs., 52.5% women). Alcohol use was self-reported. Diversity and differential species abundances were analysed and compositional differences were examined. Connections between alcohol, microbiome, inflammatory markers, and outcomes were assessed.
High-risk alcohol consumers had significantly lower bacterial diversity when compared to low-risk consumers (mean±SD:4.04±0.41 vs. 4.11±0.43). Alcohol also associated with significant shifts in overall composition and differential abundances of 344 species. These shifts were characterised by an increase in relative abundances of Gram-negative bacteria, the top genera of which were Bacteroides and Prevotella, and a decrease in putatively beneficial species in genera such as Lactobacillus, Bifidobacterium, and Akkermansia. Prospective associations with all-cause mortality (HR:1.12 [1.02—1.23]), and liver disease (HR:1.53 [1.22—1.92]) were observed.
The authors conclude that alcohol use is associated with community-level shifts in composition towards enriched Gram-negative bacteria, and diminished levels of putatively beneficial bacteria. Alcohol use associates with a proinflammatory gut microbiome profile that mediates alcohol’s effect on incident liver disease risk, possibly via increased proliferation of endotoxins through the gut epithelial lining.
Source: Koponen, K., McDonald, D., Jousilahti, P. et al. Associations of alcohol with the human gut microbiome and prospective health outcomes in the FINRISK 2002 cohort. Eur J Nutr 64, 153 (2025).